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change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 13:35
by leftfingaz
i cant find 1uF, 2.2uF and 0.01uF film. can i change it into ceramic or other caps type?

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 14:46
by karul
For 1uF and 2.2 uF, you can use Electrolytic capacitors. But pay attention to the polarity.
You may use non-polar electrolytic, as well.

For 0.01uF = 10nF you may use ceramic.

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 14:53
by leftfingaz
if there will be a change in the output sound?

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 15:20
by karul
leftfingaz wrote:if there will be a change in the output sound?
Different capacitor materials and their Influence on the sound are subject of heated debates over the internet. This forum is not an exception.

Does it matter if you have no choice. Use what you can find now.
If you can find different types, try them and see (hear) for your self.

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 15:28
by Nocentelli

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 15:39
by leftfingaz
thanks :D.. there will be no difference as long as the value is the same :D. if i use electrolytic how can i know where will be the positive if the original cap is in film

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 16:20
by karul
leftfingaz wrote:if i use electrolytic how can i know where will be the positive if the original cap is in film
If they are on power lines, then there is only one way (you should know that).

If we're talking about audio path, then It depends on the circuit.
Sometimes is better (or necessary) to use NP (non-polar) electrolytic. And you'll have no problem with the polarity.

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 16:52
by Nocentelli
For polarised electrolytic in the signal path, the negative GENERALLY should face the guitar at the input, face the amplifier at the output, and face away from the collector or emitter when connected to a transistor. Sometimes it's hard to guess, and you need to put it in the circuit then measure with a DMM. How about you post the schematic, point out which caps you want to replace with polarised and we'll have an educated guess?

Re: change film into ceramic or other caps. if it possible?

Posted: 02 Sep 2013, 17:22
by leftfingaz
karul wrote:
leftfingaz wrote:if i use electrolytic how can i know where will be the positive if the original cap is in film
If they are on power lines, then there is only one way (you should know that).

If we're talking about audio path, then It depends on the circuit.
Sometimes is better (or necessary) to use NP (non-polar) electrolytic. And you'll have no problem with the polarity.
i dont know how to figure out power line and audio path in schematic. im a total noob, but i want to learn :D :(
Nocentelli wrote:For polarised electrolytic in the signal path, the negative GENERALLY should face the guitar at the input, face the amplifier at the output, and face away from the collector or emitter when connected to a transistor. Sometimes it's hard to guess, and you need to put it in the circuit then measure with a DMM. How about you post the schematic, point out which caps you want to replace with polarised and we'll have an educated guess?
here it is
Image

i want to change C6, C9, C11, C16, C19, C24, C30, and C31. How to test the polarity in the circuit using DDM?

Re: change film into ceramic or other caps. if it possible?

Posted: 03 Sep 2013, 03:07
by leftfingaz
i figure it out, how to crawl the polarity in the circuit

Re: change film into ceramic or other caps. if it possible?

Posted: 04 Sep 2013, 21:17
by galmar
A polarised capacitor must be inserted in the following way: the + side must have a greater DC potential than the - side during idle.

This can be realised with a simple look at the schematic in general, but if it is not easy to deduce it that way, then you have to measure the DC potentials (with respect to the pedal's common point) across the two points that the capacitor will be inserted, to apply the rule I gave above. Do this using a DMM. Of course, you can't insert the capacitor beforehand and check this afterwards, since polarised capacitors will not tolerate inverse voltage, and you will end up with a blown cap if you are not lucky.

Since a capacitor blocks DC voltages, you can make these measurements with no capacitor inserted. I mean that a capacitor is not used to bias something, instead to ensure that the bias is totally affected by other circuit parameters. Unless of course a circuit is biased through the leakage current of a capacitor, which is totally wrong and I don't think I have seen it anywhere!

I hope my comment may help you a bit! :)

Re: change film into ceramic or other caps. if it possible?

Posted: 05 Sep 2013, 02:45
by leftfingaz
thank for a another answer :D